People subjected to extremely hot and dry environments for long periods are exposed to risks of body overheating and dehydration that can cause severe disorders or even death. There are several areas in which personnel must be equipped to endure such environmental conditions, for example, soldiers and guards deployed in desert climates, firefighters and steel production workers. Such individuals are supposed to wear heavy protective gear, accelerating body water loss unless the space underneath the gear, such as a vest is properly vented and cooled.
Presently, a prominent way to prevent heat buildup and resulting heavy body precipitation under a vest is the use of pre-cooled gel bags placed in special vest pockets. Such cooling technique depends on external refrigerator, can transfer body heat at uncontrolled rates and requires time for vest loading.
Some other cooling methods use water vaporization supplied into an air stream followed by heat withdrawal due to the latent energy absorption. Water mist devices can deliver water directly into an air flow created with a blower or fan. A water mist can be applied periodically to a skin or clothing making them wet. These methods can be limited to short-term relief and present water accumulation. To avoid direct water distribution in some cooling devices, it is disclosed in U.S. Pat. No. 6,189,327, for example, that blower-forced air is introduced to a body portion covered with a heat dissipating member having a liquid-retainable surface only on a side external relative to the body. However, a device operating in accordance with this principle provides the cooling effect only to body fragments, such as a neck or forehead, that is covered with the protective member.